I have a question. I'm on the birth control shot, Depo, February 25th will be my third shot. I just recently been put on an antibiotic, "Doxycycline" for a UTI. 500mg, twice a day. Question is, is it possible that antibiotics lesson the affect of Depo? I know they do with the pill, just not sure about the shot. I was told yes, did research and was told no, and called the ER since my OB isn't open, & they said its possible. & What are the chances of getting pregnant while on depo and taking antibiotics? So, does anyone have any information about my questions?